Dynamo-electric machine.



H. T'REITEL & K. SULZBERGER. DYNAMO ELECTRIC MACHINE.

APPLICATION FILED SEPT. 23, 1914.

1,1 90,048. Patented July 4, 1916.

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UNITED STATES PATENT omen.

HEINRICH TREITEL, OF CHARLOTTENBURG, AND KARL SULZBERGER, OF BERLIN,GERMANYpASSIGNORS TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEWYORK.

in order to cool the machine. In such machines, the cooling air is oftenconducted through filters in order to remove particles of dusttherefrom. For this purpose both cloth filters and so-called wet?filters are used. The latter filters are those in which the cooling airis washed by means of a fine spray of water. There is danger in the useof wet filters that the cooling air flowing therethrough may take up somuch moisturethat there will be an injurious deposition of moisture inthe machine if the parts to be cooled have a lower temperature than thecooling air, as is often the case when the machine is starting or isoperating at light load. When the air is moistened in this way, thedanger of depositing moisture on parts of the machine has been obviatedheretofore by shutting down the source of water supply whenthe machinewas starting or operating under light load; that is,

by allowing the air to enter the machine without being filtered andputting the filter into operation only when the machine has warmed up.This, however, involves the difiiculty that while the wet/filter is notin operation, the cooling fluid brings particles of dust into themachine.

When the cooling air is cleaned by means of cloth filters there isdanger of the filter catchingfire and the fire being communicated to thedynamo-electric machine by the draft of air drawn or forced into themachine by the ventilating fan. Furthermore, there is always danger insuch a machine, whether provided with filters or not, of it catchingfire due to a short-circuit in the machine or the like, in which casethe Specification of Letters Patent.

Patented July 4, 1916.

Application filed September 23, 1914. Serial No. 863,069.

continued supply of cooling air would feed the fire with fresh oxygenuntil the. ma chine is entirely destroyed.

In accordance with our invention such difficulties are avoidedby'elosing the inlet and outlet passages and connecting them together soas to provide for only a local circulation of airwithin the machine.When such an arrangement is used in a machine in which the cooling air.is conducted through wet filters, the deposition of water on themachine is avoided without the necessity of bringing unfiltered air intothe machine. When it is used in a machine provided with cloth filters,the machine may be closed against any fire that may occur in the filteror outside of the machine. Our invention may also be used in ma chineswhich may or may not be provided with filters to avoid the destructiveeffect of fire occurring in a machine. In the latter case the fire soonuses up the oxygen in. the small amount of air that is circulated and isconsequently smothered.

For a better understanding of our invention reference may be had to thefollowing description taken in connection with the accompanyingdrawings, in which the single figure shows a dynamo-electric machineembodying one form of our invention.

In the drawing, we have illustrated our invention in analternating-current dynamo-electric machine having a revolv- 1ng fieldmember 1 and a stationary armature 2. The machlne however may be of anywell known type or construction. The

machine is inclosed by a casing 3 havu'ig an inlet passage 4 and anoutlet passage 5. In order to circulate cooling fluid through themachine, fans 6 are provided, which may be mounted on the member 1 asshown. The inlet and outlet passages are closed against the outside airby a valve member 7, which at the same time connects the inlet passageto the outlet passage. As shown in the drawing, the inlet and outletpassages are preferably situated side by side and the valve member 7 iscommon to both passages. The valve member may be operatedeither by handor automatically as by a solenoid 8. This solenoid may be of whichdepends on the temperature of the dynamo-electric machine.

When the valve member 7 is in the posi tion shown in the drawing, air isdrawn through the inlet passage 4,-forced through the dynamo-electricmachine as shown by the arrows, then through the outlet passage 5,through the opening between the outlet and inlet passages as shown bythe dotted arrow and then continues in this local circulation, as bothinlet and outlet passages are closed against the outside of the machine.If the inlet passage outside of the valve member is provided with a wetfilter, no moisture can be drawn into the machine, nor can anydust-laden air be drawn therein, because of the closure of the passages.The closure of the passages also prevents any sparks being drawn intothe machine in case of a fire outside of the machine, and in case of afire within the machine the local circulation of air soon 'causes thesupply of oxygen to be consumed and the fire therefore smothered.

The thermostat 9 is shown as havingits circuit open when the machine iscool, in which the valve 7 is closed and no cooling air can be drawninto the machine. When the machine warms up, the contacts of thethermostat come together and close the circuit of the solenoid 8, whichmoves the valve member so as to close the connecting passage between theinlet and outlet passages and to open the inlet and outlet passages to,the outside, whereby the air cooled by passing through the wet filtermay be drawn in the machine. position as long as the machine is warm,but as soon as it cools off due to a decrease in load or to the machinebeing shut down, the contacts of the thermostat separate, deenergizingthe solenoid 8, whereupon the valve member 7 returns to the closedposition by means of a spring or gravity. A weight 10 is shown in thedrawing for returning it to the closed position. If desired thethermostat 9 or a second thermostat may be arranged to move the valvemember 7 into position shown in the drawing in case the machine catchesfire.

In certain cases, as in case of a fire in the machine, the thermostatmay be adjusted to close the contacts at a certain temperature and toopen them at a different temperature. We desire it to be understood thatour invention is not limited to the particular arrangements shown anddescribed and we aim in the appended claims to cover all modificationswhich do not depart from the spirit and Scope of ourinvention;

What we claim as new and desire to secure by Letters Patent of theUnited States, is,--

In-combination with a dynamo-electric The valve member stays in thismachine, an inclosing casing provided with inlet and outlet passages,means for circulating cooling fluid through said machine, means forclosing said passages and for connecting said inlet passage to saidoutlet passage to provide for local circulation within said machine, andautomatic means for operating said first mentioned means.

' 2. In combination with a dynamo-electric machine, an inclosing casingprovided with inlet and outlet passages, means for circulating coolingfluid through said machine, means for closing said passages andconnecting said inlet passage to said outlet passage to provide forlocal circulation within said machine, and means dependent upon thetemperature of said machine for operating said first mentioned means.

3. In combination with a dynamo-electric machine, an inclosing casingprovided with inlet and outlet passages, means for. circulating coolingfluid through said machine, and a valve member for closing said passagesand for connecting said inlet passage to said outlet passage to providefor local circulation within said machine.

4. In combination with a dynamo-electric machine, an inclosing casingprovided with inlet and outlet passages, means for circulating coolinfluid through said machine, a valve member for closing said passages andfor connecting said inlet passage to said outlet passage to provide forlocal circulation within said machine, and automatic means for operatingsaid valve member.

-5. In combination with a dynamo-electric machine, an inclosing casingprovided with inlet and outlet passages, means for circu lating coolingfluid through said machine, a valve member for closing said passages andfor connecting said inlet passages to said outletpassages to provide forlocal circulation within said machine, and means dependent upon thetemperature of said machine for operating said valve member.

6. In combination with a dynamo-electric machine, an inclosing casingprovided with inlet and outlet passages, means for circulating coolingfluid through said machine, said inlet and outlet passages beingsituated side by side, and a valve member common to both of saidpassages for closing said passages and for connecting said inlet passageto said outlet passage to provide for local circulation within saidmachine.

7. In combination with a dynamo-electric machine, an inclosing casingprovided with inlet and outlet passages, means for circulating coolingfluid through said machine, said inlet and outlet passages beingsituated side by side, a valve member common to both of said passagesfor closing said passages and for connecting said inlet passage to saidoutlet passage to provide for local circulation within said machine, andmeans dependent upon the'temperature of said machine for operating saidvalve member.

In Witness whereof, we have hereunto set 15 our hands this first day ofSeptember, 1914.

HEINRICH TREITEL. KARL SL'LZBERGER.

side by side, a valve member common to both of said passages for closingsaid passages 10 and for connectlng said inlet passage to said outletpassage to provide for local circula Witnesses .Itur's ROXXLAXD,Aim-"nan \VoLr.

It is hereby certified that in Letters Patent No. 1,190,048, grantedJuly 4, 1916,

upon the application of Heinrich Treitel, of Charlottenburg, and KarlSulzberger,

of Berlin, Germany, for an improvement 'in Dynamo-Electric Machines, anerror appears in the printed specification requiring correction asfollows: Page 2, line 28,

after the Word which insert the Word case; and that the said LettersPatent should be read with this correction therein that the same mayconform to the record of the case in the Patent Office.

Signed and sealed this 22d day of August, A. D., 1916.

[SEAL] F. W. H. CLAY,

Acting Commissioner of Patents.

